Client-Driven Shared Secret Updates for Client Authentication

ABSTRACT

Techniques are provided for client-driven shared secret updates for client authentication. One method comprises, in response to a first authentication of a client by a server using a given shared secret, updating, by the client, the given shared secret to generate an updated shared secret and storing the updated shared secret with the server; and submitting the updated shared secret to the server as part of a second authentication of the client. The updating is optionally performed by one or more of a password vault and a browser extension. The client may randomly select the updated shared secret or compute the updated shared secret in a predefined manner. The server may evaluate whether the client stores the updated shared secret with the server in connection with the first authentication and implement one or more predefined steps when the updated shared secret is not stored with the server.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application is related to U.S. patent application Ser. No.______, entitled “Authentication Based on Shared Secret Seed Updates forOne-Time Passcode Generation,” (Attorney Docket No. 113657.01); and U.S.patent application Ser. No. ______, entitled “Authentication Based onShared Secret Updates,” (Attorney Docket No. 113658.01), each filedcontemporaneously herewith and incorporated by reference herein.

FIELD

The field relates generally to information processing systems, and moreparticularly to authentication techniques in such systems.

BACKGROUND

Many modern authentication solutions are based upon a client provingknowledge to a server of a shared secret value, such as a password, apersonal identification number, or a symmetric key. Similarly, one-timepasscode solutions leverage shared knowledge of a shared secret seed toperform time-based or counter-based computations by the client and theserver to prove knowledge of the shared secret seed. While efficient,such shared secret cryptography techniques suffer from an inability toensure that only one client shares a given shared secret with theserver. The continued assumption that only the one client and the serverhave the shared secret cannot be verified.

A need therefore exists for improved techniques for protecting sharedsecrets.

SUMMARY

In one embodiment, a method comprises, in response to a firstauthentication of a client by a server using a given shared secret,updating, by the client, the given shared secret to generate an updatedshared secret and storing the updated shared secret with the server; andsubmitting the updated shared secret to the server as part of a secondauthentication of the client.

In some embodiments, the updating is performed by one or more of apassword vault and a browser extension. The server may evaluate whetherthe client stores the updated shared secret with the server inconnection with the first authentication and implement one or morepredefined steps when the updated shared secret is not stored with theserver. In at least one embodiment, the client randomly selects theupdated shared secret.

Other illustrative embodiments include, without limitation, apparatus,systems, methods and computer program products comprisingprocessor-readable storage media.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an information processing system configured for performingauthentication in one embodiment of the disclosure;

FIG. 2 shows another information processing system configured forperforming authentication in at least one embodiment of the disclosure;

FIG. 3 is a system diagram of an exemplary mobile device on which atleast one embodiment of the disclosure can be implemented;

FIG. 4 is a system diagram of exemplary mobile device components, inaccordance with one embodiment of the disclosure;

FIG. 5 is a flow diagram of a client-driven shared secret update processfor client authentication, according to one illustrative embodiment ofthe disclosure;

FIG. 6 illustrates a chain of shared secrets, according to an embodimentof the disclosure;

FIG. 7 illustrates an exemplary processing platform that may be used toimplement at least a portion of one or more embodiments of thedisclosure comprising a cloud infrastructure; and

FIG. 8 illustrates another exemplary processing platform that may beused to implement at least a portion of one or more embodiments of thedisclosure.

DETAILED DESCRIPTION

Illustrative embodiments of the present disclosure will be describedherein with reference to exemplary communication, storage and processingdevices. It is to be appreciated, however, that the disclosure is notrestricted to use with the particular illustrative configurations shown.One or more embodiments of the disclosure provide methods, apparatus andcomputer program products for client-driven shared secret updates forclient authentication.

In one or more embodiments, techniques are provided for client-drivenshared secret evolution that leverage previous communications betweentwo parties to evolve the shared secret in a known way. In someembodiments, if the shared secret is used by a third party without theknowledge of the client, upon future communication with the client, theserver can detect an inconsistency indicating the use of the sharedsecret by the third party. Remediation actions can then be implementedto establish a new shared secret known only by the client and server.

One challenge in shared secret authentication is ensuring that theshared secret remains unknown to other parties. Existing attempts toprotect the shared secret involve, for example, dedicated securehardware, layered encryption, password vaults, and other techniques.However, the core assumption of these authentication systems is that theshared secret is only known to the client and server. These secrets areoften valid for a long period of time and breaking the assumption ofsecrecy can lead to significant adverse consequences.

Moreover, if an attacker can intercept the channel between the clientand the server, an opportunity exists for a Man-in-the-Middle (MITM)attack, whereby the attacker accesses the transmission from the clientto the server to obtain the shared secret then the attacker uses theone-time passcode (OTP) to authenticate as the client (or a user of theclient). While this can be overcome under some circumstances, thedisclosed solution also provides a detection capability for such anattack.

In one or more embodiments, the disclosed client-driven shared secretevolution techniques update the shared secret of a user (orcorresponding client) to create a chain of shared secrets. This sharedsecret evolution is driven by use of the current shared secret. When agiven shared secret is used for authentication, the given shared secretis updated based on some aspect of the authentication to create a newshared secret, as discussed hereinafter. As both the client and serverobserve the successful authentication, in some embodiments, they canboth update their copy of the shared secret, creating a chain of sharedsecret values. In this manner, should the shared secret be compromised,the server can observe an inconsistency in authentication attempts thatwould indicate that the shared secret information is being leveraged bymultiple clients, as discussed further below. Generally, the server candetect and respond to cloning and other attacks or anomalies, such asMI™ attacks. In some situations, the authentication server may not knowwhich authentication attempt was invalid. It may be unknown, forexample, whether the current user is a legitimate user or an “attacker.”Moreover, there could be situations where an alert would be raised thatis not actually an attack, but represents an anomaly. In the case ofclient-drive shared secret updates, especially if there is networkdisruption between the client and server, an update sent by the clientto the authentication server for storage may not be received by theauthentication server (which is not necessarily an attack, but rathermay be considered an anomaly).

One or more embodiments of the disclosure recognize that the disclosedclient-driven shared secret evolution techniques can leverage a passwordvault and/or a browser extension to perform a password change againstthe server, as would be apparent to a person of ordinary skill in theart. Each time a user is authenticated, the password vault (and/orbrowser extension) generates a new shared secret and changes the sharedsecret at the server with the newly computed shared secret. In thiscase, the shared secret update is a one-sided operation performed by theclient device. The client generates a new shared secret and notifies theserver of the updated shared secret value. Among other benefits, theserver can decouple authentication from shared secret updates (serverscurrently perform these functions today),

In addition, the disclosed client-driven shared secret update techniquesfor client authentication optionally leverage the pattern of oneexpected action following another expected action to detect potentialattackers, as discussed hereinafter. If a user always changes theirshared secret upon a login and does not do so for a new login attempt,the server can observe this behavior and respond appropriately (e.g.,forcing a step-up authentication). If an attacker, knowing this is thepolicy, changes the shared secret, the new shared secret would beunknown to the legitimate user. Thus, at the next login attempt by theuser, the shared secret would fail, and the user would be made aware ofan issue (e.g., a potential compromise of the shared secret). Serverlogic and/or a policy can ensure that the shared secret was not changedtwice to bypass this detection (e.g., once to a new value, and then backto the original shared secret so the valid user login would occurcorrectly).

In some embodiments, the shared secret is modified by a client deviceafter a successful authentication attempt by using information from theauthentication as part of a shared secret update protocol to generate anupdated shared secret. The information from the authenticationcomprises, for example, a timestamp of the authentication, a randomvalue used in the authentication, and a substantially unique value usedin the authentication. By incorporating this information from theauthentication into the updated shared secret, and thus, the nextauthentication attempt, an authentication chain is created (in a similarmanner as blocks in a blockchain containing pointers to previousblocks).

FIG. 1 shows a computer network 100 configured in accordance with anillustrative embodiment of the disclosure. The computer network 100comprises a plurality of user devices 102-1, 102-2, . . . 102-M,collectively referred to herein as user devices 102. The user devices102 are coupled to a network 104, where the network 104 in thisembodiment is assumed to represent a sub-network or other relatedportion of the larger computer network 100. Accordingly, elements 100and 104 are both referred to herein as examples of “networks” but thelatter is assumed to be a component of the former in the context of theFIG. 1 embodiment. Also coupled to the network 104 is a processingplatform 105.

The user devices 102 may comprise, for example, mobile telephones,laptop computers, tablet computers, desktop computers or other types ofcomputing devices. Such devices are examples of what are more generallyreferred to herein as “processing devices.” Some of these processingdevices are also generally referred to herein as “computers.”

The user devices 102 in some embodiments comprise respective computersassociated with a particular company, organization or other enterprise.In addition, at least portions of the computer network 100 may also bereferred to herein as collectively comprising an “enterprise network.”Numerous other operating scenarios involving a wide variety of differenttypes and arrangements of processing devices and networks are possible,as will be appreciated by those skilled in the art.

Also, it is to be appreciated that the term “user” in this context andelsewhere herein is intended to be broadly construed so as to encompass,for example, human, hardware, software or firmware entities, as well asvarious combinations of such entities.

The network 104 is assumed to comprise a portion of a global computernetwork such as the Internet, although other types of networks can bepart of the computer network 100, including a wide area network (WAN), alocal area network (LAN), a satellite network, a telephone or cablenetwork, a cellular network, a wireless network such as a Wi-Fi or WiMAXnetwork, or various portions or combinations of these and other types ofnetworks. The computer network 100 in some embodiments thereforecomprises combinations of multiple different types of networks, eachcomprising processing devices configured to communicate using internetprotocol (IP) or other related communication protocols.

The processing platform 105 has an associated database 106 configured tostore shared secret information 107 that optionally includes each sharedsecret used for authentication by a user and a corresponding timestampwhen a given shared secret was used, as discussed further below.

As discussed further below in conjunction with FIGS. 5 and 6, in orderto detect inconsistencies in an authentication chain of shared secrets,the server can optionally store some additional data as part of theshared secret information 107, beyond a current shared secret value. Invarious embodiments, the stored additional data varies, depending onwhat the client sends to the server as part of an authenticationattempt. For example, the server can store the timestamp of theauthentication when a particular shared secret was used. Assuming thatthe client and the server can agree on the time of an authentication(for example, within some predefined tolerance), the client and theserver can both use that information to update their secretsappropriately.

In some embodiments, the timestamp is not needed. In such embodiments,reused secrets are detected by checking if the supplied authenticationinformation is correct for any previous secret. This approach may beimpractical due to performance reasons (e.g., having to search a largenumber of previously submitted secrets for prior authentication attemptsof a given user). Thus, storing the timestamp along with the previouslysubmitted secrets allows the server to efficiently detect reusedsecrets, with the assumption that the client provides the timestamp ofthe last known successful authentication (from the view of the client)when submitting a current authentication.

The database 106 in the present embodiment is implemented using one ormore storage systems associated with the processing platform 105. Suchstorage systems can comprise any of a variety of different types ofstorage including, for example, network-attached storage (NAS), storagearea networks (SANs), direct-attached storage (DAS) and distributed DAS,as well as combinations of these and other storage types, includingsoftware-defined storage.

Also associated with processing platform 105 are input-output devices108, which illustratively comprise keyboards, displays or other types ofinput-output devices in any combination. Such input-output devices areused to support one or more user interfaces to the processing platform105, as well as to support communication between the processing platform105 and other related systems and devices not explicitly shown.

In one or more embodiments of the disclosure (such as the exampleembodiment depicted in FIG. 1), the processing platform 105 comprises anauthentication server 112. Authentication events, such as an evaluationof a shared secret submitted by a user, initiated at respective ones ofthe user devices 102, are directed to the authentication server 112 overthe network 104 for processing. The authentication server 112 candetermine if a given access attempt is authentic, based on an evaluationof the responsive shared secret from the user submitted in response to achallenge. Upon verification of the presented authentication factors,the authentication server 112 grants the requesting user device 102access to one or more protected resources of the computer network 100(such as further depicted in FIG. 2, for example). Although shown as anelement of the processing platform 105 in this embodiment, theauthentication server 112 in other embodiments (such as depicted in FIG.2, for example) can be implemented at least in part externally to theprocessing platform 105, for example, as a stand-alone server, set ofservers or other type of authentication system coupled to the network104.

The processing platform 105 in the FIG. 1 embodiment is assumed to beimplemented using at least one processing device. Each such processingdevice generally comprises at least one processor and an associatedmemory, and implements one or more functional modules for controllingcertain features of the processing platform 105.

More particularly, the processing platform 105 in this embodimentcomprises a processor 120 coupled to a memory 122 and a networkinterface 124.

The processor 120 illustratively comprises a microprocessor, amicrocontroller, an application-specific integrated circuit (ASIC), afield-programmable gate array (FPGA) or other type of processingcircuitry, as well as portions or combinations of such circuitryelements.

The memory 122 illustratively comprises random access memory (RAM),read-only memory (ROM) or other types of memory, in any combination. Thememory 122 and other memories disclosed herein may be viewed as examplesof what are more generally referred to as “processor-readable storagemedia” storing executable computer program code or other types ofsoftware programs.

One or more embodiments of the disclosure include articles ofmanufacture, such as computer-readable storage media. Examples of anarticle of manufacture include, without limitation, a storage devicesuch as a storage disk, a storage array or an integrated circuitcontaining memory, as well as a wide variety of other types of computerprogram products. The term “article of manufacture” as used hereinshould be understood to exclude transitory, propagating signals.

The network interface 124 allows the processing platform 105 tocommunicate over the network 104 with the user devices 102, andillustratively comprises one or more conventional transceivers.

The processor 120 further comprises an enrollment module 130 and anauthentication and shared secret update module 132.

It is to be appreciated that this particular arrangement of modules 130and 132 illustrated in the processor 120 of the FIG. 1 embodiment ispresented by way of example only, and alternative arrangements can beused in other embodiments. For example, the functionality associatedwith the modules 130 and 132 in other embodiments can be distributedacross multiple processing nodes, or separated across a larger number ofmodules within processor 120. As another example, multiple distinctprocessors can be used to implement different ones of the modules 130and 132 or portions thereof.

At least portions of the enrollment module 130 and/or authentication andshared secret update module 132 may be implemented at least in part inthe form of software that is stored in memory 122 and executed byprocessor 120. Similarly, at least portions of the authentication server112 of the processing platform 105 can be implemented at least in partin the form of software that is stored in memory 122 and executed byprocessor 120.

It is to be understood that the particular set of elements shown in FIG.1 for authentication of a user in authentication processes involvinguser devices 102 of computer network 100 is presented by way ofillustrative example only, and in other embodiments additional oralternative elements may be used. Thus, another embodiment may includeadditional or alternative systems, devices and other network entities,as well as different arrangements of modules and other components.

By way of example, in other embodiments, the processing platform 105 canbe eliminated and associated elements such as authentication server 112,enrollment module 130 and/or authentication and shared secret updatemodule 132 can be implemented elsewhere in the computer network 100.

An exemplary process utilizing authentication and shared secret updatemodule 132 of the processing platform 105 in computer network 100 willbe described in more detail with reference to the flow diagram of FIG.5.

FIG. 2 is a system diagram of an illustrative embodiment of thedisclosure. By way of illustration, FIG. 2 depicts an alternativeembodiment to FIG. 1, wherein the authentication server(s) 112 is/arenot resident on the processing platform 105 or user device(s) 102, butrather are separate devices. Accordingly, as depicted in FIG. 2, userdevice 102 communicates with a protected resource 270 a over network104. As detailed further below, at least one embodiment of thedisclosure can also include a user device 102 that includes a protectedresource 270 b residing thereon. In an example implementation, a userauthenticates online with one or more authentication servers 112-1through 112-N (hereinafter, collectively referred to as authenticationservers 112) before obtaining access to protected resource 270 a and/or270 b (hereinafter, collectively referred to as protected resource 270unless otherwise specified).

According to one aspect of the disclosure, as noted above, the user ofthe user device 102 is authenticated by authentication servers 112 usinga shared secret of the user, and/or other forms of cryptographicinformation. The exemplary communications among the system elements 102,104 and 270 of FIG. 2 employed to achieve authentication by theauthentication servers 112 are discussed further below.

It is to be appreciated that a given embodiment of the disclosed systemmay include multiple instances of user device 102 and protected resource270, and possibly other system components, although only singleinstances of such components are shown in the simplified system diagramof FIG. 2 for clarity of illustration.

As noted herein, user device 102 may represent a portable device, suchas a mobile telephone, personal digital assistant (PDA), wireless emaildevice, game console, etc. The user device 102 may alternativelyrepresent a desktop or laptop personal computer (PC), a microcomputer, aworkstation, a mainframe computer, a wired telephone, a television settop box, or any other information processing device which can benefitfrom the use of authentication techniques in accordance with thedisclosure.

The user device 102 may also be referred to herein as simply a “user.”The term “user,” as used in this context, should be understood toencompass, by way of example and without limitation, a user device, aperson utilizing or otherwise associated with the device, or acombination of both. An operation described herein as being performed bya user may therefore, for example, be performed by a user device, aperson utilizing or otherwise associated with the device, or by acombination of both the person and the device. Similarly, a password,biometric sample, OTP, or other cryptographic information described asbeing associated with a user may, for example, be associated with a userdevice 102, a person utilizing or otherwise associated with the device,or a combination of both the person and the device.

As also depicted in FIG. 2, the authentication servers 112 can beassociated with a third party entity, such as an authenticationauthority, that processes authentication requests on behalf of webservers and other resources, as well as verifies the cryptographicinformation that is presented by a user device 102.

Further, the protected resource 270 may be, for example, anaccess-controlled application, data store, web site or hardware device.In other words, a protected resource 270 is a resource that grants useraccess responsive to an authentication process, as will be described ingreater detail below. For example, protected resource 270 a may includean access-controlled file, an e-mail, a protected application, a remoteapplication server such as a web site or other software program orhardware device that is accessed by the user device 102 over a network104.

Additionally, in at least one embodiment of the disclosure, protectedresource 270 b can include one or more applications or data residing onthe user device 102 itself. For example, such a protected resource 270 bcan include access to a mobile data management container for launchingapplications on the user device 102 (such as a mobile device), which canbe protected requiring authentication in order to run the application(s)protected by the container. Further, protected resource 270 b could alsoinclude an access-controlled file, e-mail, protected application, remoteapplication server such as a web site or other software program orhardware device that is accessed by the user device 102 over network104. Similarly, it is possible that in order to unlock the mobileplatform to perform operations, a successful authentication might berequired.

FIG. 3 is a system diagram of an exemplary mobile device 300 on which atleast one embodiment of the disclosure can be implemented. By way ofillustration, as shown in FIG. 3, the exemplary mobile device 300comprises a user interface 303 configured to receive user input andprovide user output, such as a data file and/or data file locationselection(s), such as described herein. One or more embodiments of thedisclosure can include components such as a display screen, a capacitivetouch display, and a push-button keyboard implemented for use inconnection with the user interface 303.

Additionally, the mobile device 300 includes a network interface 305configured to connect the mobile device 300 to a communications mediumsuch as, for example, Wi-Fi and/or cellular telephony. Accordingly, thenetwork interface 305 enables the mobile device 300 to communicate withthe other components of an electronic environment.

The mobile device 300 further comprises a memory 309 configured to storeone or more software constructs including, for example, an operatingsystem 311, an authentication and shared secret updating application313, data for protected resources 315 (e.g., documents and restrictedapplications), a cryptographic information file 317, as well as othersuitable or relevant material.

In one or more embodiments, processing circuitry 307 of the mobiledevice 300 is configured to operate in accordance with the softwareconstructs stored in the memory 309. By way of example, when theprocessing circuitry 307 runs the operating system 311, the processingcircuitry 307 provides a secure electronic platform on which a user isable to carry out work. Such an electronic platform is capable ofoperating, for example, as a container to protect data requiring userauthentication before permitting access. Further, when the processingcircuitry 307 runs the authentication and shared secret updatingapplication 313, the processing circuitry 307 communicates with a localauthentication client 325 in a secure manner, for example, to obtaincryptographic information 317(a), 317(b) from a storage buffer 327 andwith a server to update a shared secret stored by the server, asadditionally described herein.

Additionally, for completeness, cellular phone circuitry 319 withinmobile device 300 allows the user to establish cellular phone calls withother callers having remote devices, as would be appreciated by oneskilled in the art.

It should be appreciated that the processing circuitry 307 can includeone or more processors running specialized software components, such asdetailed in connection with the techniques detailed herein and furtherdepicted in FIG. 4.

In at least one embodiment of the disclosure, once the mobile device 300is able to obtain valid cryptographic information, the user of themobile device 300 is able to perform local user authentication to accessprotected resources. Accordingly, as noted, the mobile device 300 isprovisioned with the authentication and shared secret updatingapplication 313 and cryptographic information file 317 holdingcryptographic information to be used in connection with anauthentication process. For example, and as further detailed herein,such cryptographic information within cryptographic information file 317can include one or more shared secrets of the user in some embodiments.

Consequently, the processing circuitry 307 of the mobile device 300 canperform a local authentication operation using cryptographic informationfile 317 stored in the memory 309. In at least one embodiment of thedisclosure, the processing circuitry 307 runs the authentication andshared secret updating application 313, which directs the user of themobile device 300, via the user interface 303, to enter cryptographicinformation (such as, for example, shared secrets of the user) which iscaptured as one or more input elements 317(a), 317(b), etc. While thecaptured cryptographic information 317(a), 317(b), etc. is temporarilystored in the storage buffer 327 of the local authentication client 325,the authentication and shared secret updating application 313 evaluatesthe captured user-provided cryptographic information 317(a), 317(b),etc. using a shared secret of the user (e.g., provided during enrollmentin file 317) to determine a likelihood of a match and/or plausibility ofthe user-provided cryptographic information. In addition, following theauthentication, the authentication and shared secret updatingapplication 313 stores an updated shared secret with the server.

If a match or otherwise positive resolution is determined via thisevaluation, the authentication and shared secret updating application313 permits the user to access a protected resource (such as, forexample, data in association with element 315 that are stored in thememory 309).

FIG. 4 is a system diagram of exemplary mobile device components, inaccordance with at least one embodiment of the disclosure. As depictedin FIG. 4, a user can enter cryptographic information via user interface303. This entered cryptographic information is captured as one or moreinput elements 317(a), 317(b). Such input elements can include, as notedabove, the user-provided shared secret of the user.

Accordingly, the captured one or more input elements 317(a), 317(b),etc. can be stored in cryptographic information file 317 to besubsequently used in conjunction with fuzzy logic to carry out anauthentication process.

Consequently, a corresponding cryptographic flow (carried out, forexample, by authentication and shared secret updating application 313 asrun by operating system 311) can take the following exemplary form. Theuser is prompted (via user interface 303) as part of a challenge toenter cryptographic information in connection with an authenticationrequest to access a protected resource associated with the mobile device(for example, the user wishes to access and/or unlock his or her smartphone). The entered cryptographic information is captured by theprocessing circuitry 307 as one or more input elements 317(a), 317(b)that are temporarily stored in the storage buffer 327 of the localauthentication client 325.

Subsequently, the authentication and shared secret updating application313 evaluates the captured user-provided cryptographic information317(a), 317(b), etc. with the original challenge in file 317 stored inmemory 309 to determine a likelihood of a match and/or plausibility ofthe user-provided response(s). If the user-entered input elements317(a), 317(b) are deemed to be matching and/or plausible,authentication is deemed successful and the user is granted access tothe protected resource in question. In addition, following theauthentication, the authentication and shared secret updatingapplication 313 stores an updated shared secret with the server.

FIG. 5 is a flow diagram of an exemplary client-driven shared secretupdate process for client authentication 500, according to oneillustrative embodiment. As shown in FIG. 5, a test is initiallyperformed during step 510 to determine if a client is authenticatedusing a given shared secret. Once it is determined during step 510 thata client has been authenticated using the given shared secret, theclient updates the given shared secret during step 520 to generate theupdated shared secret and stores the updated shared secret with theserver. As used herein, the storage of the updated shared secret by theclient with the server shall be broadly construed to encompass theclient storing the updated shared secret with the server withoutparticipation by the server, as well as the client providing the updatedshared secret to the server for storage by the server. In someembodiments, the information from the authentication used for theupdated shared secret comprises a timestamp of the authentication, arandom value used in the authentication, and/or a substantially uniquevalue used in the authentication.

In one or more embodiments, the update performed during step 520comprises an exclusive OR (XOR) operation or a hash operation applied tothe given shared secret and the information from the authentication. Ina further variation, the client randomly selects the updated sharedsecret, as the client and the authentication server do not need tocompute the same updated shared secret value, so the client can justcreate a new secret value and store the updated shared secret with theauthentication server. It is noted that, in some embodiments, the clientand the server both independently update the shared secret upon asuccessful authentication. The secret can be updated when necessary, forexample, using one or more of the following techniques:

-   -   the current shared secret is hashed with the current timestamp        to create a new shared secret;    -   the current timestamp is passed through a key derivation        function or a hash function and the result XORed with the        current shared secret;    -   other aspects of the authentication could also be included in        the secret update function, such as the domain or authentication        device associated with the authentication could be hashed        together with the timestamp and the previous shared secret to        create a new shared secret; and    -   if a nonce is used as part of authentication, the nonce could        optionally be included in the secret update function as well.

The exemplary client-driven shared secret update process for clientauthentication 500 then submits the updated shared secret to the serveras part of a second authentication of the client during step 530.

An attack is optionally detected by the server during step 540 when theclient attempts a new authentication using a shared secret and theserver determines that the shared secret was previously used forauthentication. Finally, upon such a detected attack, a recoveryworkflow is initiated during step 550. For example, a reset workflow canbe initiated to limit how long an attacker can potentially access theaccount of the user.

As part of the authentications of steps 510 and 530, the client canoptionally communicate the timestamp of the prior authentication to theserver. As noted above, the stored shared secret information 107optionally includes each shared secret used for authentication by a userand a corresponding timestamp when a given shared secret was used. Inthis manner, the server can use the communicated timestamp of the priorauthentication to access and evaluate the shared secret used with theprior authentication when evaluating a current authentication.Furthermore, if the channel between the client and the server is abi-directional channel, then the server can notify the client that theauthentication succeeded and that the secret state needs to be updated.On the client side, a browser extension or a password vault could beemployed to make a client-side shared secret update process seamlesswhen interacting with web sites.

It is noted that the shared secret is shared between the client and theauthentication server in the sense that once the client updates thegiven shared secret and stores the updated shared secret with theauthentication server during step 520, both the client and theauthentication server have a copy of the shared secret and the sharedsecret is shared between them. The authentication server will use theupdated shared secret as part of the next authentication attempt.

FIG. 6 illustrates a shared secret chain 600, according to oneillustrative embodiment of the disclosure. As shown in FIG. 6, duringstep 610, a user authenticates with a shared secret 620 (Shared Secret).During step 630, the user updates the shared secret 620 to generate anupdated shared secret 640 (Shared Secret′) and stores the updated sharedsecret 640 with the server (for example, using the exemplaryclient-driven shared secret update process for client authentication 500of FIG. 5). In some embodiments, the updated shared secret 640 is afunction of the prior shared secret 620.

As shown in FIG. 6, during step 650, the user authenticates to theserver with the updated shared secret 640 (Shared Secret′). During step660, the server authenticates the client using the updated shared secret640 or detects an attack.

Assume that an attacker intercepted the updated shared secret 640 (e.g.,using a MI™ attack) and then authenticates with the updated secret 640(e.g., using a hash of the password of the user) prior to step 650 at atime t₀. In connection with the authentication of the attacker at timet₀, the updated shared secret 640 is further updated to a new sharedsecret (e.g., Secret″). The new shared secret is a function of theupdated secret 640.

The user then attempts to authenticate with the updated secret 640(e.g., the last shared secret value known to the user) during step 650.Thus, when the real user attempts to authenticate, the authenticationfails because the shared secret of the user is no longer up-to-date withthe server (e.g., the updated secret 640 was already changed inconnection with the attacker authentication at time t₀). Thus, an attackis detected at state 660.

In some embodiments, attack detection can occur in real-time inconnection with the authentication, or attack detection can be deferreduntil a later time (e.g., every night the server could perform batchprocessing to analyze failed authentications, for example, depending onthe number of users of the system).

The disclosed client-driven shared secret update techniques thus allowdetection after-the-fact. If, during authentication, the client providesa reference to what the client believes is the previous secret (or otherdata that allows the server to look up the previously used sharedsecret), the server would be able to identify a fork in theauthentication chain. A fork can be considered a deviation from anexpected evolution of a secret. The server could recognize that a usersubmitted a valid authentication for a previously used secret, but thatwas invalid for the current authentication due to another client forkingthe chain of shared secrets 600 at a previous time. Upon detection, theserver can invalidate the shared secret of the user and force a recoveryworkflow (e.g., a reset workflow) in order to limit how long an attackercan potentially access the account of a user. The server can alsorequire additional authentication factors to login as part of therecovery workflow. Further, the server can optionally take additionalactions as part of the recovery workflow, including notifying the useror triggering an internal protocol to investigate a possible breach.

In some embodiments, the chaining of shared secrets in the manner shownin FIG. 6 enables the server to potentially detect whether a breach hasoccurred, in which secrets of multiple users have been stolen. Bymonitoring the number of forked authentication chains across a userpopulation, for example, the server can observe anomalies and takeaction. For example, if the number of detected forked authenticationchains spikes to above-normal levels (e.g., based on a predefinedthreshold or another criteria), an internal protocol could be triggeredthereby requiring all users to require step-up authentication until apossible breach can be investigated and/or resolved.

The particular processing operations and other network functionalitydescribed in conjunction with the flow diagrams of FIGS. 5 and 6 arepresented by way of illustrative example only, and should not beconstrued as limiting the scope of the disclosure in any way.Alternative embodiments can use other types of processing operations toupdate a shared secret responsive to an authentication of a user. Forexample, the ordering of the process steps may be varied in otherembodiments, or certain steps may be performed concurrently with oneanother rather than serially.

In one or more embodiments, the disclosed techniques for authenticatinga user using client-driven shared secret updates optionally include adetection mechanism for detecting if a shared secret is used by morethan one client (e.g., cloning), or if an authentication is captured andused by an attacker (e.g., Man-in-the-Middle attack). In some instances,the disclosed client-driven secret evolution techniques can be used toprevent such attacks.

Among other benefits, the disclosed techniques for authenticating a userusing client-driven shared secret updates that chain successfulauthentications together significantly reduce the valid lifetime of ashared secret, for example, from an order of years down to an order ofhours (or even less). Thus, the risk of a stolen secret is significantlyreduced, since the window for authentication is much smaller (e.g.,attackers can no longer indefinitely authenticate after stealing ashared secret).

One or more embodiments of the disclosure provide improved methods,apparatus and computer program products for authentication usingclient-driven shared secret updates. The foregoing applications andassociated embodiments should be considered as illustrative only, andnumerous other embodiments can be configured using the techniquesdisclosed herein, in a wide variety of different applications.

It should also be understood that the disclosed authenticationtechniques, as described herein, can be implemented at least in part inthe form of one or more software programs stored in memory and executedby a processor of a processing device such as a computer. As mentionedpreviously, a memory or other storage device having such program codeembodied therein is an example of what is more generally referred toherein as a “computer program product.”

The disclosed techniques for authenticating a user using client-drivenshared secret updates may be implemented using one or more processingplatforms. One or more of the processing modules or other components maytherefore each run on a computer, storage device or other processingplatform element. A given such element may be viewed as an example ofwhat is more generally referred to herein as a “processing device.”

As noted above, illustrative embodiments disclosed herein can provide anumber of significant advantages relative to conventional arrangements.It is to be appreciated that the particular advantages described aboveand elsewhere herein are associated with particular illustrativeembodiments and need not be present in other embodiments. Also, theparticular types of information processing system features andfunctionality as illustrated and described herein are exemplary only,and numerous other arrangements may be used in other embodiments.

In these and other embodiments, compute services can be offered to cloudinfrastructure tenants or other system users as a Platform-as-a-Service(PaaS) offering, although numerous alternative arrangements arepossible.

Some illustrative embodiments of a processing platform that may be usedto implement at least a portion of an information processing systemcomprise cloud infrastructure including virtual machines implementedusing a hypervisor that runs on physical infrastructure. The cloudinfrastructure further comprises sets of applications running onrespective ones of the virtual machines under the control of thehypervisor. It is also possible to use multiple hypervisors eachproviding a set of virtual machines using at least one underlyingphysical machine. Different sets of virtual machines provided by one ormore hypervisors may be utilized in configuring multiple instances ofvarious components of the system.

These and other types of cloud infrastructure can be used to providewhat is also referred to herein as a multi-tenant environment. One ormore system components such as a cloud-based authentication engine, orportions thereof, are illustratively implemented for use by tenants ofsuch a multi-tenant environment.

Cloud infrastructure as disclosed herein can include cloud-based systemssuch as Amazon Web Services (AWS), Google Cloud Platform (GCP) andMicrosoft Azure. Virtual machines provided in such systems can be usedto implement at least portions of a cloud-based authentication platformin illustrative embodiments. The cloud-based systems can include objectstores such as Amazon S3, GCP Cloud Storage, and Microsoft Azure BlobStorage.

In some embodiments, the cloud infrastructure additionally oralternatively comprises a plurality of containers implemented usingcontainer host devices. For example, a given container of cloudinfrastructure illustratively comprises a Docker container or other typeof Linux Container (LXC). The containers may run on virtual machines ina multi-tenant environment, although other arrangements are possible.The containers may be utilized to implement a variety of different typesof functionality within the storage devices. For example, containers canbe used to implement respective processing devices providing computeservices of a cloud-based system. Again, containers may be used incombination with other virtualization infrastructure such as virtualmachines implemented using a hypervisor.

Illustrative embodiments of processing platforms will now be describedin greater detail with reference to FIGS. 7 and 8. These platforms mayalso be used to implement at least portions of other informationprocessing systems in other embodiments.

FIG. 7 shows an example processing platform comprising cloudinfrastructure 700. The cloud infrastructure 700 comprises a combinationof physical and virtual processing resources that may be utilized toimplement at least a portion of the disclosed authentication system. Thecloud infrastructure 700 comprises multiple virtual machines (VMs)and/or container sets 702-1, 702-2, . . . 702-L implemented usingvirtualization infrastructure 704. The virtualization infrastructure 704runs on physical infrastructure 705, and illustratively comprises one ormore hypervisors and/or operating system level virtualizationinfrastructure. The operating system level virtualization infrastructureillustratively comprises kernel control groups of a Linux operatingsystem or other type of operating system.

The cloud infrastructure 700 further comprises sets of applications710-1, 710-2, . . . 710-L running on respective ones of theVMs/container sets 702-1, 702-2, . . . 702-L under the control of thevirtualization infrastructure 704. The VMs/container sets 702 maycomprise respective VMs, respective sets of one or more containers, orrespective sets of one or more containers running in VMs.

In some implementations of the FIG. 7 embodiment, the VMs/container sets702 comprise respective VMs implemented using virtualizationinfrastructure 704 that comprises at least one hypervisor. Suchimplementations can provide authentication functionality of the typedescribed above for one or more processes running on a given one of theVMs. For example, each of the VMs can implement authentication controllogic and associated client-driven shared secret update techniques forproviding authentication functionality for one or more processes runningon that particular VM.

An example of a hypervisor platform that may be used to implement ahypervisor within the virtualization infrastructure 704 is the VMware®vSphere® which may have an associated virtual infrastructure managementsystem such as the VMware® vCenter™. The underlying physical machinesmay comprise one or more distributed processing platforms that includeone or more storage systems.

In other implementations of the FIG. 7 embodiment, the VMs/containersets 702 comprise respective containers implemented using virtualizationinfrastructure 704 that provides operating system level virtualizationfunctionality, such as support for Docker containers running on baremetal hosts, or Docker containers running on VMs. The containers areillustratively implemented using respective kernel control groups of theoperating system. Such implementations can provide authenticationfunctionality of the type described above for one or more processesrunning on different ones of the containers. For example, a containerhost device supporting multiple containers of one or more container setscan implement one or more instances of authentication control logic andassociated client-driven shared secret update features for use inprotecting shared secrets.

As is apparent from the above, one or more of the processing modules orother components of the authentication server 112 may each run on acomputer, server, storage device or other processing platform element. Agiven such element may be viewed as an example of what is more generallyreferred to herein as a “processing device.” The cloud infrastructure700 shown in FIG. 7 may represent at least a portion of one processingplatform. Another example of such a processing platform is processingplatform 800 shown in FIG. 8.

The processing platform 800 in this embodiment comprises at least aportion of the given system and includes a plurality of processingdevices, denoted 802-1, 802-2, 802-3, . . . 802-K, which communicatewith one another over a network 804. The network 804 may comprise anytype of network, such as a WAN, a LAN, a satellite network, a telephoneor cable network, a cellular network, a wireless network such as WiFi orWiMAX, or various portions or combinations of these and other types ofnetworks.

The processing device 802-1 in the processing platform 800 comprises aprocessor 810 coupled to a memory 812. The processor 810 may comprise amicroprocessor, a microcontroller, an ASIC, an FPGA or other type ofprocessing circuitry, as well as portions or combinations of suchcircuitry elements, and the memory 812, which may be viewed as anexample of a “processor-readable storage media” storing executableprogram code of one or more software programs.

Articles of manufacture comprising such processor-readable storage mediaare considered illustrative embodiments. A given such article ofmanufacture may comprise, for example, a storage array, a storage diskor an integrated circuit containing RAM, ROM or other electronic memory,or any of a wide variety of other types of computer program products.The term “article of manufacture” as used herein should be understood toexclude transitory, propagating signals. Numerous other types ofcomputer program products comprising processor-readable storage mediacan be used.

Also included in the processing device 802-1 is network interfacecircuitry 814, which is used to interface the processing device with thenetwork 804 and other system components, and may comprise conventionaltransceivers.

The other processing devices 802 of the processing platform 800 areassumed to be configured in a manner similar to that shown forprocessing device 802-1 in the figure.

Again, the particular processing platform 800 shown in the figure ispresented by way of example only, and the given system may includeadditional or alternative processing platforms, as well as numerousdistinct processing platforms in any combination, with each suchplatform comprising one or more computers, storage devices or otherprocessing devices.

Multiple elements of an information processing system may becollectively implemented on a common processing platform of the typeshown in FIG. 7 or 8, or each such element may be implemented on aseparate processing platform.

For example, other processing platforms used to implement illustrativeembodiments can comprise different types of virtualizationinfrastructure, in place of or in addition to virtualizationinfrastructure comprising virtual machines. Such virtualizationinfrastructure illustratively includes container-based virtualizationinfrastructure configured to provide Docker containers or other types ofLXCs.

As another example, portions of a given processing platform in someembodiments can comprise converged infrastructure such as VxRail™,VxRack™, VxBlock™, or Vblock® converged infrastructure commerciallyavailable from VCE, the Virtual Computing Environment Company, now theConverged Platform and Solutions Division of Dell EMC.

It should therefore be understood that in other embodiments differentarrangements of additional or alternative elements may be used. At leasta subset of these elements may be collectively implemented on a commonprocessing platform, or each such element may be implemented on aseparate processing platform.

Also, numerous other arrangements of computers, servers, storage devicesor other components are possible in the information processing system.Such components can communicate with other elements of the informationprocessing system over any type of network or other communication media.

As indicated previously, components of an information processing systemas disclosed herein can be implemented at least in part in the form ofone or more software programs stored in memory and executed by aprocessor of a processing device. For example, at least portions of thefunctionality shown in one or more of the figures are illustrativelyimplemented in the form of software running on one or more processingdevices.

It should again be emphasized that the above-described embodiments arepresented for purposes of illustration only. Many variations and otheralternative embodiments may be used. For example, the disclosedtechniques are applicable to a wide variety of other types ofinformation processing systems. Also, the particular configurations ofsystem and device elements and associated processing operationsillustratively shown in the drawings can be varied in other embodiments.Moreover, the various assumptions made above in the course of describingthe illustrative embodiments should also be viewed as exemplary ratherthan as requirements or limitations of the disclosure. Numerous otheralternative embodiments within the scope of the appended claims will bereadily apparent to those skilled in the art.

What is claimed is:
 1. A method, comprising: in response to a firstauthentication of a client by a server using a given shared secret,updating, using at least one processing device of the client, the givenshared secret to generate an updated shared secret and storing theupdated shared secret with the server; and submitting the updated sharedsecret to the server as part of a second authentication of the client.2. The method of claim 1, wherein the given shared secret is updatedusing information from the first authentication as part of a secretupdate protocol to generate the updated shared secret.
 3. The method ofclaim 2, wherein the information from the first authentication comprisesone or more of a timestamp of the first authentication, a random valueused in the first authentication, and a substantially unique value usedin the first authentication.
 4. The method of claim 1, wherein the givenshared secret comprises one or more of a password, a cryptographic key,a cryptographic symmetric key, a personal identification number, and ashared secret seed used to derive one-time passcodes.
 5. The method ofclaim 1, wherein the updating is performed by one or more of a passwordvault and a browser extension.
 6. The method of claim 1, wherein theserver evaluates whether the client stores the updated shared secretwith the server in connection with the first authentication andimplements one or more predefined steps when the updated shared secretis not stored with the server.
 7. The method of claim 1, wherein ananomaly is detected when the client attempts the second authenticationusing a particular shared secret and the server determines that theparticular shared secret was previously used for an authentication. 8.The method of claim 7, wherein, in response to the anomaly beingdetected, the server initiates a predefined recovery workflow.
 9. Themethod of claim 7, wherein the server detects a breach of shared secretsof multiple users by monitoring a number of said detected anomaliesacross a user population.
 10. The method of claim 1, wherein the updatecomprises one or more of: (i) one or more of an exclusive OR (XOR)operation and a hash operation applied to the given shared secret andinformation from the first authentication; and (ii) the client randomlyselecting the updated shared secret.
 11. The method of claim 1, whereinthe client receives a notification, from the server, of one or more ofthat the first authentication succeeded and that the given shared secretneeds to be updated.
 12. A system, comprising: a memory; and at leastone processing device, coupled to the memory, operative to implement thefollowing steps: in response to a first authentication of a client by aserver using a given shared secret, updating, by the client, the givenshared secret to generate an updated shared secret and storing theupdated shared secret with the server; and submitting the updated sharedsecret to the server as part of a second authentication of the client.13. The system of claim 12, wherein the updating is performed by one ormore of a password vault and a browser extension.
 14. The system ofclaim 12, wherein the server evaluates whether the client stores theupdated shared secret with the server in connection with the firstauthentication and implements one or more predefined steps when theupdated shared secret is not stored with the server.
 15. The system ofclaim 12, wherein an anomaly is detected when the client attempts thesecond authentication using a particular shared secret and the serverdetermines that the particular shared secret was previously used for anauthentication.
 16. The system of claim 12, wherein the update comprisesone or more of: (i) one or more of an exclusive OR (XOR) operation and ahash operation applied to the given shared secret and information fromthe first authentication; and (ii) the client randomly selecting theupdated shared secret.
 17. A computer program product, comprising atangible machine-readable storage medium having encoded thereinexecutable code of one or more software programs, wherein the one ormore software programs when executed by at least one processing deviceperform the following steps: in response to a first authentication of aclient by a server using a given shared secret, updating, by the client,the given shared secret to generate an updated shared secret and storingthe updated shared secret with the server; and submitting the updatedshared secret to the server as part of a second authentication of theclient.
 18. The computer program product of claim 17, wherein theupdating is performed by one or more of a password vault and a browserextension.
 19. The computer program product of claim 17, wherein theserver evaluates whether the client stores the updated shared secretwith the server in connection with the first authentication andimplements one or more predefined steps when the updated shared secretis not stored with the server.
 20. The computer program product of claim17, wherein the update comprises one or more of: (i) one or more of anexclusive OR (XOR) operation and a hash operation applied to the givenshared secret and the information from the first authentication; and(ii) the client randomly selecting the updated shared secret.